Endocrine Week 4 Part 3 Study Guide Questions

ENDOCRINE WEEK 4 PART 3 STUDY GUIDE QUESTIONS 1. a. What are the different classifications of Addison’s disease? (3 marks) b. For each of the classes, describe diagnostic tests, that will help you differentiate it, from the other classes. (3 marks). c. In a patient with Addison’s disease, a patient may go into a cardiogenic shock. (2 marks). Answer: a. • • • b. Primary -> issue with the adrenal gland. Secondary -> issue with the pituitary. Tertiary -> issue with the hypothalamus. To differentiate between primary and secondary Addison’s disease, a patient should be given ACTH. If cortisol production rises, this means that there is an issue which the pituitary and thus a secondary Addisson’s. If it does not rise, this means that there is an adrenal issue, which means there is a primary Addisson’s disease. To find out if it is tertiary (hypothalamic issue), perform a CRH stimulation test. If cortisol production rises, this means that the hypothalamus is impaired, it does not rise, this means that there is either a primary or a secondary cause. c. This is because there is reduced cortisol production. Cortisol is responsible for increase SNS sensitivity of the SNS. When there are reduced levels of cortisol there will be a downregulation of alpha- and beta-adrenergic receptors in the smooth muscle (tunica media layer) of blood vessels and the heart receptivity. This means that there will be vasodilation and reduced cardiac output and pacemaker activity respectively. Due to this, there will by hypotension, which will cause a cardiogenic shock. 2. Contrast the mechanism of action between fludrocortisone and mineralocorticoid antagonists and their indications. (2 marks). Answer: Fludrocortisone is a mineralocorticoid intercellular receptor agonist. When it binds to it, it will activate it and will perform the functions of alderstone, such as increasing Na/K+ ATPases on the basolateral sides of the tubule and epithelial Na+ channels and k+ channels on the apical side of the tubule. This can be used for conditions, when there is decrease alderstone synthesis, such as the case with Addison’s disease. In contrast, mineralocorticoid antagonist it blocks mineralocorticoid intercellular receptor, which will block it from binding with alderstone and preventing it from undergoing the described functions. This can be used in conditions, where there is hyper alderstone production, such as the case with functional adrenal tumours. 3. a. Distinguish between adrenal adenomas and carcinomas. (3 marks) b. What are the different types of adrenal adenomas. (1 mark). Answer: a. • • b. Adrenal adenomas: About 4 cm big. Have regular shape and borders. Have 50% of contrast washed within 10 minutes of injection. Adrenal carcinomas: More than 4 cm big. Irregular shape and boarders. Evidence of necrosis and calcification. Functional and non-functional. Functional is a tumor that releases hormones. Non-functional, is a tumor that does not release hormones, and this accounts for the majority of adrenal tumours. 4. Explain why a patient with hyperthyroidism may experience tremors or show seizure like symptoms. (1 mark). Answer: This is because thyroid hormones increase AP, increase dendrite and synapse formation. IMPORTANT STUFF 5. Describe the sensory role of the hypothalamus. Answer: • • - Internal: Has a preotic nucleus -> senses and regulates temperature. Exposed to hormones, glucose and solutes in the blood -> controls hunger and satiety, as well as hydration. External: Olfactory: feeding and behaviour. Photoreceptors: provided by the retinal input over the 24-hour cycle. Since the input fluctuates this controls the sleep/wake cycle. Anterolateral system: signals tissue damage. Visceral afferent: via the nucleus solitaries. This is directly replayed via the brainstem (autonomic related) structures.